Re: [PATCH] mm: memcontrol.c: move mem_cgroup_id_get_many under CONFIG_MMU

From: Michal Hocko
Date: Tue Dec 17 2019 - 10:13:48 EST


On Tue 17-12-19 10:04:36, Qian Cai wrote:
>
>
> > On Dec 17, 2019, at 9:46 AM, Michal Hocko <mhocko@xxxxxxxxxx> wrote:
> >
> > yes, I would just ignore this warning. Btw. it seems that this is
> > enabled by default for -Wall. Is this useful for kernel builds at
> > all? Does it realistically help discovering real issues? If not then
> > can we simply blacklist it?
>
> -Wunused-function is useful in-general as it caught many dead code
> that some commits left unintentionally with real-world configs.

I do understand the general purpose of the warning. I am simply not sure
the kernel tree is a good candidate with a huge number of different
config combinations that might easily result in warnings which would
tend to result in even more ifdeferry than we have.
--
Michal Hocko
SUSE Labs